Well, Marc obviously heard a difference.
One of the problems with beds is that there's no standardized way of delivering them. Could be 5.1, 7.1 or higher. Why install 5 front speakers if an unknown number of mixes make use of only 3 of them?
From the Dolby white paper: "Dolby Atmos therefore supports “beds” in addition to audio objects. Beds are effectively channel-based submixes or stems. These can be delivered for final playback (rendering) either individually or combined into a single bed, depending on the
desire of the content creator. These beds can be created in different channel-based configurations such as 5.1, 7.1, or even future formats such as 9.1 (including arrays of overhead loudspeakers)."
With objects a virtually unlimited number of channels is the basis. Better reproduction systems would benefit - for each and every mix.
Anyway, my original point was "realism". Beds might be enough for most mixes but if increased realism is the goal then reverberation has to be presented from more and/or different locations than beds can provide.
Edited by markus767 - 7/4/12 at 4:13pm